PC cards, which generally have printed circuits, are available in three types defined by PCMCIA (Personal Computer Member Card International Association) standards. All three cards have a width and length of 54 mm.times.85.6 mm, with maximum thicknesses of 3.3 mm, 5 mm, and 10.5 mm, with the type 11 cards (thickness of 5 mm) being the most common type. Standard PC cards have front connectors with 68 pin contacts. More recent standard PC cards have become available with rear connectors for connecting to a variety of devices. U.S. Pat. No. 5,411,402 describes a PC card rear connector of a type that is commonly used, which has a row of pin contacts and which has an undercut slot at the middle to enable a device to be locked to the rear connector when mated thereto. That patent describes a connector device at the end of a cable for mating and latching to the rear connector of the PC card.
There has arisen the need for an adaptor for connection to the rear of a PC card, where the adaptor can receive a smart card and connect the pads on a face of the smart card to the terminals at the rear of the PC card. A smart card is a card constructed in accordance with International standards. It contains a memory accessible from contact pads on a surface of the card, and the card generally has a thickness of no more than about 1 mm. It would be desirable if the adaptor was reliably held to the PC card when the adaptor held a PC card, to avoid interruption in the passage of signals between the two cards. It also would be desirable if the adaptor extended a minimum distance behind the PC card.